In the field of semiconductor manufacturing, rear-surface grinding which grinds the rear surface of a wafer is performed to form a semiconductor wafer (to be referred to as a “wafer” hereinafter) such as a silicon wafer into a thin film.
As a processing device performing rear-surface grinding to a wafer, as described in Patent Literature 1, a planarizing device in which a cassette containing stage, an alignment stage, a coarse-grinding stage, a fine-grinding stage, a polishing stage, a polishing cloth cleaning stage, a polishing cloth dressing stage, and a wafer cleaning stage are set to cause an index table to move a wafer between the stages is known. In such a planarizing device, two grinding stones cantilevered from the distal ends of a grinding stone feeding device arranged outside the index table are disposed, respectively, one of the grinding stones coarsely grinds the wafer, and the other finely grinds the wafer.
The processing device, as shown in FIG. 9A, includes a column 91, a spindle 93 cantilevered from the column 91 through a ball screw 92, a grinding stone 94 attached to the lower end of the spindle 93, the spindle 93 is moved downward by the ball screw 92 while the spindle 93 is rotated, and a wafer W placed on a chuck 95 is ground by the grinding stone 94.